ThingSpeakWrite() limit only 33% more in Home version than free, should that be?

The following code runs up to jj=500 in the Free version, and up to jj=700 in the Home version.

[ed: Free version and Home version of ThingSpeak channel]

But the account counters don't show any daily usage yet.

Thanks for help understanding where the input 4 entry data from a battery analyzer totals 4 columns x 27036 entries. But jj can't be anywhere near that! Thanks, Mark @W4CHL

% Send data to Grinspector test channel via thingSpeakWrite()
% 09-09 Student version limited, set jj = Max_records ~500, 
% 09-10 Home version also limited, but to same jj = ~700 ! Should be larger!?
tspchid = 861393;   jj = 700;
tStamps = datetime("2019-08-30") + seconds(gt_data(1:jj,1));
gt_timetable = timetable(tStamps, gt_data(1:jj,2), gt_data(1:jj,3), gt_data(1:jj,4));
thingSpeakWrite(tspchid,gt_timetable,'WriteKey','write-key');

Output for jj > 700:
>> gt_7t_plot_thspk

gt_fn = 

    "7tCurrieLiFe1-7tCurrieLiFe1.csv"

input file is 7tCurrieLiFe1-7tCurrieLiFe1.csv 
Time to read the dataset:  0.28 sec 
Time to parse the dataset: 0.0005 sec 
Time to loop by row over the dataset:  0.99 sec 
Time to plot the dataset:  0.12 sec 
Error using gt_7t_plot_thspk (line 125)
URL is incorrectly formed, or the requested feature is not supported in this version of ThingSpeak.
 

[Hans Scharler]

73s.

Where is this code snipit from? What is the structure of the CSV file? I will try to figure out what's going on. Thanks.

[Walter Roberson]

There is no Free version of MATLAB.

If you are referring to a Trial license, then the Trial license is fully operational, except that it watermarks Report Generator reports, and that executables generated by MATLAB Compiler in a Trial license expire.

This suggests that the fact that it is a Home release is not what is making the difference.

[MR Smith]

73s

The code snippet is mine for importing battery charge/discharge data to analyze and share at our upcoming Light EV Tech course.

The free ThingSpace account channel has different limits than the Home ThingSpace account. We have used my MATLAB student account online and a Trial Windows R2019a with same results.

Yes, we were using same data file repeatedly, so had to clear the channel each time to prevent the URL conflict error. We also had to break up data to send into 500 record chunks (ThingSpeak free account channel) or 700 record chunks (ThingSpeak Home channel). A typical 7 hour charge/discharge repeat cycling has 25000 records, though we could and should resample with an adaptive filter to minimize the number of records over slowly varying sections of time.

No matter what Matlab account was used or ThingSpace target channel, the thingSpaceWrite() required a 15s delay between chunks.

The goal is to stream data to ThingSpeak from the battery testing and offer the code snippets via copyleft as part of our course materials.

Thank you all for comments! They helped narrow down the multiple constraints encountered. I will post a service request to get the 15sec delay down to the 1sec we expect with ThingSpace Home channel.

Best, Mark @W4CHL 73 de Mark W4CHL

[MR Smith]

Oh and here is the result from one test, others are in queue.

https://thingspeak.com/channels/862228

[Walter Roberson]

Ah, this appears to refer to https://thingspeak.com/prices/thingspeak_home

[Walter Roberson]

"The code snippet is mine for importing battery charge/discharge data to analyze and share at our upcoming Light EV Tech course."

That is not Personal Use, so a Home license is not appropriate.

Answer 1

[Christopher Stapels]

A side note: "URL is incorrectly formed,..." generally comes from writing non unique timestamps to a ThingSpeak channel. You cannot have two entries that have the same timestamp.

[MR Smith]

TX, your comment led us to clear channel before resubmitting test file.

Answer 2

[Vinod]

There are multiple levels of counters on https://thingspeak.com/account. The table shows the number of messages remaining and is accurate to within the last 10 minutes as it is kept track of by a process that runs every 5 minutes. The daily usage is only calculated once a day, so you really have to wait until the time rolls over to the next day (UTC time) for the daily charts to show it. Likewise, monthly charts are produced after the end of the month.

How frequently are you writing a block of data using thingSpeakWrite, and how many rows are in each block of data?

If you describe your application in more detail, I may be able to give you suggestions on thing to try for efficient utilization of ThingSpeak and MATLAB analysis on ThingSpeak.

[SL: removed period from link.]

[MR Smith]

Tx, given the advice here we have made a great deal of progress on our applications with ThinkSpeak!